Cable structures suitable for hauling and power and signal transmission are typically used in oil wells for the installation, operation and retrieval of electrical submersible pumps. Prior art cable used for this purpose is generally flat and comprises a core of power and hauling lines surrounded by a helically-wound interlocked armor tape.
An example of a prior art cable of this type is disclosed in U.S. Pat. No. 4,644,094 and assigned to the same assignee as the instant application.
To chemically treat bottom hole oil wells, a hollow flexible tubing, which may be composed of steel, is inserted into the well. This tubing serves as the conduit through which an appropriate treatment fluid, such as liquid nitrogen, is able to be injected into the well. A pair of coacting endless traction belts is typically used for driving the tubing into and out of the particular bore hole. This type of drive means normally has its belts oriented vertically, directly above the surface of the bore hole. The tubing is gripped tightly between the coacting belts which rotate to impart axial movement to the tubing. A powered reel is used to store, pay out and accumulate the tubing.
Inasmuch as a source of pushing and pulling forces is available with the coacting traction belts, it would be advantageous to have a cable which could also effectively utilize the traction belts as a means for forcing it and any equipment attached to the cable's down-hole end past obstructions and deviations in the bore hole. To be able to utilize the available drive means effectively, the cable structure preferably should possess the feature of being able to efficiently convert the available drive forces into high-magnitude pushing and pulling forces which can be concentrated along the longitudinal axis of the cable structure and hence, parallel to the desired direction of cable translation. The aforementioned prior art cable lacks this feature.